Abstract: Ustiloxins are cyclopeptide mycotoxins produced by the false smut pathogen (teleomorph: Claviceps oryzae-sativae; anamorph: Ustilaginoidea virens) of rice. They are toxic to plants and animals especially for their cytotoxic activity to be antimitotic by inhibition of microtubule assembly and cell skeleton formation. Ustiloxins can be used for medicinal and agrochemical purposes acting as antitumor, antifungal and insecticidal agents. The classification, isolation and purification, detection and analysis of the ustiloxins along with their broad range of biological activities are briefly reviewed in this paper.